[PATCH] net: phy: dp83869: fix interrupts issue, not correctly handled when operate with an optical fiber sfp.

[chalianis1@gmail.com]

From: Anis Chali <chalianis1@gmail.com>

to correctly clear the interrupts both status registers must be read.

from datasheet: http://ti.com/lit/ds/symlink/dp83869hm.pdf
7.3.6 Interrupt
The DP83869HM can be configured to generate an interrupt when changes of internal status occur. The interrupt
allows a MAC to act upon the status in the PHY without polling the PHY registers. The interrupt source can be
selected through the interrupt registers, MICR (12h) and FIBER_INT_EN (C18h). The interrupt status can be
read from ISR (13h) and FIBER_INT_STTS (C19h) registers. Some interrupts are enabled by default and can
be disabled through register access. Both the interrupt status registers must be read in order to clear pending
interrupts. Until the pending interrupts are cleared, new interrupts may not be routed to the interrupt pin.

Signed-off-by: Anis Chali <chalianis1@gmail.com>
---
 drivers/net/phy/dp83869.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/phy/dp83869.c b/drivers/net/phy/dp83869.c
index a62cd838a9ea..98d773175462 100644
--- a/drivers/net/phy/dp83869.c
+++ b/drivers/net/phy/dp83869.c
@@ -25,6 +25,7 @@
 #define DP83869_CFG2		0x14
 #define DP83869_CTRL		0x1f
 #define DP83869_CFG4		0x1e
+#define DP83869_FX_INT_STS	0xc19
 
 /* Extended Registers */
 #define DP83869_GEN_CFG3        0x0031
@@ -195,6 +196,12 @@ static int dp83869_ack_interrupt(struct phy_device *phydev)
 	if (err < 0)
 		return err;
 
+	if (linkmode_test_bit(ETHTOOL_LINK_MODE_FIBRE_BIT, phydev->supported)) {
+		err = phy_read_mmd(phydev, DP83869_DEVADDR, DP83869_FX_INT_STS);
+		if (err < 0)
+			return err;		
+	}
+
 	return 0;
 }
 
-- 
2.49.0